Seems like the Nazis managed to do the Concentration Camps thing without facial recognition software.
America and Canada used facial recognition for their ww2 concentration camps.
https://en.m.wikipedia.org/wiki/Internment_of_Japanese_Canad...
The Nazis utilised the best information-management tools of the time, including IBM computers (fully supported by IBM throughout the war) and punch cards (as another commenter notes: <https://news.ycombinator.com/item?id=42359352>). Those tattoos worn by concentration camp survivors were IBM-assigned identifiers.
Nazis also used census and other civil data sources. Deliberate destruction of such records in the Netherlands is one of the legacies of WWII:
<https://en.wikipedia.org/wiki/The_Holocaust_in_the_Netherlan...>
This and other legacies of 20th-century genocide are chief reasons why European attitudes toward rampant data collection and exchange are far harsher than in the United States. Though I'd argue still not nearly harsh enough.
But they did have tremendous data processing abilities for their time!